OVENBIRDS: Furnariidae

PHYSICAL CHARACTERISTICS

Ovenbirds, also called horneros (or-NEYR-ohz), are small- to medium-sized, rust-to-brown colored birds. They have slender, pointed bills that range in length from short to long. Their wings are relatively short and are rounded or pointed at the tips. Ovenbirds have medium length legs and feet with front toes that are joined at the base. These birds have rufous, reddish, heads and white throats in many species. There is a light stripe over the eyes. They have brownish backs, light brown-and-white speckled or streaked bellies, rufous wings with brownish red or white bands, and rufous tails. Males and females are similarly colored. Adults are 5 to 11 inches (13 to 28 centimeters) long and weigh 0.3 to 1.6 ounces (9 to 46 grams).

GEOGRAPHIC RANGE

Ovenbirds are found from central Mexico to Patagonia in southern South America.

HABITAT

Ovenbirds inhabit forests of various types, brushlands, pampas (grasslands), alpine areas (high mountain regions), and semi-deserts.

DIET

Their diet consists of mostly insects, spiders, other invertebrates, animals without backbones, and sometimes small seeds. They forage, search for food, among litter on the ground, in foliage, leaves, and on bark and epiphytes (EPP-uh-fytes), plants such as mosses that grow on another plant but do not depend on that host plant for nutrition, of shrubs and trees.

BEHAVIOR AND REPRODUCTION

Ovenbirds do not migrate, and are found usually alone or as a breeding pair, but sometimes in small groups. Some species are found primarily on the ground and others remain mostly in trees. When foraging on the ground they tend to walk and hop. While foraging in trees, some species are very quick as they search through foliage and finer branches, while other species are very agile as they forage on tree trunks. Some species are strong flyers, while others are weak and unable to fly long distances. Their calls are harsh and scolding, and their songs consist of a series of whistles and trills.

Ovenbirds build various shapes and types of nests. Many species build loose nests of plant fibers such as twigs and moss inside a cavity in a tree, among rocks, or in dense foliage. Other species make nests of lumps of moist clay, each about 0.1 ounces (3 grams) in weight, which is carried inside the bill. When completed, the nest looks like an oven, often weighing about 10 pounds (4 kilograms). One mated pair of ovenbirds may work on several nests at the same time. Other species dig tunnels from 3 to 10 feet (1 to 3 meters) long into an earthen bank or cliff. Still other species build small, spherical, hanging nests in trees, which are entered from a hole underneath. The last species group builds the largest of ovenbird nests, up to 3 feet (1 meter) in height, with several chambers enclosed inside the nest.

OVENBIRDS ARE NAMED FOR A NEST

Rufous horneros build rounded nests out of moist clay, like a traditional clay baker's oven. They first build a base, often on a stout tree branch. They bring in small clumps of clay, mud, and some straw and hair to the construction site with their bill. The outer walls are built next, followed by the roof, which is dome-shaped. An entrance hole is left on one of the sides. Inside, a lining is made of fine fibers of soft grass and other plant tissues.

Females lay two to six eggs that are usually white but can be blue or greenish. Both parents share in egg incubation, sitting on the eggs, and in the care of nestlings, young birds unable to leave nest, and fledglings, birds that has recently grown the feathers needed for flight. The incubation period is fifteen to twenty-two days, and the nestling period, time necessary to take care of young birds unable to leave nest, is thirteen to twenty-nine days.

OVENBIRDS AND PEOPLE

The ovenbird species called the rufous hornero is the national bird of Argentina. Birdwatchers like to view these birds. There is little other significance between ovenbirds and people.

CONSERVATION STATUS

Three species of ovenbirds are listed as Critically Endangered, facing an extremely high risk of extinction, no longer existing, in the wild. Nine species are listed as Endangered, facing a very high risk of extinction in the wild in the near future, and fifteen species are Vulnerable, facing a high risk of extinction in the wild. There are eighteen species considered Near Threatened, in danger of becoming threatened with extinction.

RUFOUS HORNERO (Furnarius rufus): SPECIES ACCOUNTS

Physical characteristics: Rufous horneros are large ovenbirds with slightly rounded to nearly square tails. They have short-to-medium, pointed bills that are almost straight. The upper part of the bill is a brownish gray, to grayish or dark brownish while the lower part of the bill is pale horn to pinkish with a dark tip. They have rufous-brown foreheads and dull brown crowns, top of head. This species has a tan stripe over the eyes. Their throats are whitish with very rufous hindnecks, back of the neck. The back and rump are rufous-brown with some pale edgings and the belly is pale buff or tan. Their flanks, sides, are tawny, copper color. The primary feathers are dull brownish with light rufous wingbands. Their tails are somewhat rufous in color and their lower legs and toes are grayish, brownish, or blackish. Males and females are similar in color. Juveniles are paler on the undersides. Adults are 6.3 to 9.1 inches (16 to 23 centimeters) long and weigh between 1.1 and 2.3 ounces (31 and 65 grams).

Geographic range: They are widely found in Bolivia, much of southern Brazil, Paraguay, Uruguay, and northern and central Argentina.

Habitat: Rufous horneros usually inhabit scrublands, pastures, agricultural lands, urban parks, and gardens. They are often found near streams, rivers, ponds, or lakes; usually in lowlands but they can be found to about 8,200 feet (2,500 meters), and occasionally up to 12,150 feet (3,500 meters).

Diet: Their diet consists of insects, other small invertebrates, and seeds. The bird forages on the bare ground and among leaf litter, often probing into soft dirt with its bill.

Behavior and reproduction: Rufous horneros do not migrate. They are usually found alone or in pairs on the ground where they run and hop, and perch in open spaces within shrubs. Their song is a loud, fast, rhythmic series of notes such as "kweep!" and their calls include a sharp "jeet!," "jeah," or "krip," often sounded as a series of notes. Pairs of birds often sing back and forth with each other.

The breeding season of the monogamous (muh-NAH-guh-mus), having only one mate, birds is in the spring-summer, September to February. Rufous horneros will defend their breeding territory, where they construct a large nest made up of thousands of small clumps of moist mud, clay, some dung, and straw carried to a nest site with their bills. The inside of the nest is lined with bits of grasses and stems. The spherical, oven-shaped structure is usually placed on a tree stump, fencepost, telephone pole, or rooftop; but can also be placed on older nests, bare ground, or rock. The entrance is usually placed on the side of the nest. Two to five eggs are laid from September to December. The incubation period is fourteen to eighteen days. Both males and females incubate eggs and take care of the nestlings. The nestling period is twenty-three to twenty-six days.

Rufous horneros and people: The rufous hornero is the national bird of Argentina. They are often found near human dwellings.

Conservation status: Rufous horneros are not threatened with extinction. They are widespread and abundant throughout their habitat. ∎

GREATER THORNBIRD (Phacellodomus ruber): SPECIES ACCOUNTS

Physical characteristics: Greater thornbirds are the reddest in color and among the largest in size of the ovenbirds. This species has a stout, plump, body and a long tail. They have a short, pointed bill that is slightly downcurved. The upper part of the bills is blackish and the lower part of the bill is pale gray to grayish green. They have a rufous-brown to grayish brown face with a light brown stripe over the eyes. There is a reddish chestnut crown with faint pale shaft streaks; a rufous cap on the head; and a reddish brown to olive-brown hindcrown. Wings are rufous-chestnut. They have brown backs, rufous tails and whitish bellies and throats. Their rumps are brown tinged with red and their toes are gray to olive. Sexes are similar in appearance. Juveniles lack the crown patch and have a mottled, speckled, brownish breast. Adults are 7.5 to 8.3 inches (19 to 21 centimeters) long and weigh between 1.2 to 1.8 ounces (35 and 51 grams).

Geographic range: They are found in Bolivia, central Brazil, Paraguay, northern Argentina, and, possibly, in far northern Uruguay.

Habitat: Greater thornbirds inhabit the undergrowth of humid tropical forests, thickets on the banks of waterways, woodlands and scrublands. They especially like to be near ponds and other surface waters. They are found from sea level to elevations up to 4,600 feet (1,400 meters).

Diet: Their food includes insects, ants, and other small invertebrates. They are usually found foraging on the forest floor, around dense vegetation, and near the edges of water bodies such as marshes.

Behavior and reproduction: Greater thornbirds move about cautiously, not wanting to be seen. They usually move about alone or in pairs. Their song is a long series of loud, abrupt, accelerating notes such as "chip," with a sharp call of "check check" and "chweet." Their breeding season is from October to January. They build large, bulky nests that look similar to a cylinder or cone. The birds use sticks, twigs, and branches, often thorny ones, as materials to build the nest, which often contains several chambers and has a side entrance at the lower end. The interior of the nest is usually lined with fine grasses and feathers. The nest is usually attached to an outer, drooping branch of a tree or other low vegetation. Females lay three to five eggs, but five eggs are rare. Both sexes incubate the eggs and raise the nestlings.

Greater thornbirds and people: There is no known significance between people and greater thornbirds.

Conservation status: Greater thornbirds are not threatened with extinction. They are widespread and locally abundant throughout most of their habitats. They are protected in parts of their range, such as Pantanal National Park in Brazil and Esteros del Iberá and Calilegua National Parks in Argentina. ∎

FOR MORE INFORMATION

Books:

del Hoyo, Josep, Andrew Elliott, Jordi Sargatal, Jose Cabot, et al., eds. Handbook of the Birds of the World. Barcelona: Lynx Edicions, 1992.

Dickinson, Edward C., ed. The Howard and Moore Complete Checklist of the Birds of the World, 3rd ed. Princeton, NJ and Oxford, U.K.: Princeton University Press, 2003.

Forshaw, Joseph, ed. Encyclopedia of Birds, 2nd ed. San Diego, CA: Academic Press, 1998.

Harrison, Colin James Oliver. Birds of the World. London and New York: Dorling Kindersley, 1993.

Perrins, Christopher M., and Alex L. A. Middleton, eds. The Encyclopedia of Birds. New York: Facts on File, 1985.